The present study is concerned with the application of the transfer of cellular immunity by immune RNA (I-RNA) to the immunotherapy of tumors. In animal studies utilizing a syngeneic mouse tumor-host system, the duration of tumor specific immunity transferred by normal syngeneic spleen cells incubated in vitro with I-RNA capable of transferring tumor-specific immunity will be looked for and the efficacy of tumor specific immuniy transferred by I-RNA will be studied in an immunotherapy protocol which involves the prevention of metastases following excision of a primary tumor. Comparison will be made of in vitro correlates of tumor specific immunity and the results of immunotherapy in vivo. The mechanism of I-RNA mediated transfer of tumor immunity will also be investigated in several in vitro systems.